Overvolting a 36v Q100 motor

suddenurge

Finding my (electric) wheels
Nov 10, 2015
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0
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Hi,

I am new to the forum and since two months I am also a first time ebike owner looking for some help. I have ordered a 48v battery to increase the speed on my ebike which is currently running a 36v q100 350w 201rpm in a 26 inch tyre. Having read some of the posts on this topic, I understand that the controller is the key to avoid burning the motor. If someone knowledgeable could comment on the following solutions, I would be very grateful.

I should mention that it is pretty flat where I live, although it is very windy. I am constantly giving the motor full throttle and I also pedal vigorously using a 52-11 teeth setup to achieve maximum speed. I rarely drop below 27 kmh (17 mph) even when climbing hills. Average speed is about 30-35 kmh (18.5-22 mph) depending on how the wind blows.

1. I have opened my current controller on one side to take peek inside and I can distinguish 63v on one of the can shaped things.

Am I right to assume that this must be one of the capacitors? Could there be anything else stamped with 63v than the capacitors? The reason I am asking is that this can shaped thing is lying down instead of standing up as I have seen in pictures of capcitors in controllers.

Since I am currently running a 36v battery with this controller, do I need to worry about the max current of the controller also? Could i determine the max current if I properly opened up the controller and looked at the transistors?

2. I have also considered buying the s-lcd-3 +s12sh (800w 35a) combination and set the controller to halve the current giving me 17,5 amps of max output. Has anyone confirmed that the controller actually succeeds in limiting the current output as advertised? Otherwise I would probably burn the motor pretty quickly.

3. I also understand that you could buy the KU93 or ku123 controllers and file down one of the shunts to decrease max current. I don't see myself doing any soldering on the remaining shunt. Which one would you recommend?

4. Lastly, I have found this 350w 17a 36v/48V compatible controller on ebay

http://www.ebay.com/itm/Brushless-Controller-For-E-bike-Scooter-with-without-Hall-Sensor-36V-48V-350W-/321867901730?hash=item4af0d26b22:g:08gAAOSwKIpV-i4J

The seller has no knowledge on how many mosfets it contains. Do you think this could be a viable option or is it just cheap junk?

I know this is a very long first post, but I did not want to leave anything out. Again, I would really appreciate comments and pros/cons of the different solutions. Other possible solutions are also greatly appreciated.
 

Alan Quay

Esteemed Pedelecer
Dec 4, 2012
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Devon
....
1. I have opened my current controller on one side to take peek inside and I can distinguish 63v on one of the can shaped things.

Am I right to assume that this must be one of the capacitors? Could there be anything else stamped with 63v than the capacitors? The reason I am asking is that this can shaped thing is lying down instead of standing up as I have seen in pictures of capcitors in controllers.

Since I am currently running a 36v battery with this controller, do I need to worry about the max current of the controller also? Could i determine the max current if I properly opened up the controller and looked at the transistors?
.
Yes, that's a capacitor. Lying down or standing up is no problem.

Open it up and post some pics. 6 FET is normally around 15a, 9 is 22a, 12 is 30a.

If you solder the shunt a bit you can get a few more amps from the controller. 17a should be easy to do.
 
Last edited:

anotherkiwi

Esteemed Pedelecer
Jan 26, 2015
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2. I have also considered buying the s-lcd-3 +s12sh (800w 35a) combination and set the controller to halve the current giving me 17,5 amps of max output. Has anyone confirmed that the controller actually succeeds in limiting the current output as advertised? Otherwise I would probably burn the motor pretty quickly.
The assistance level sets the current. From the manual:

03 Maximum current value÷2.00
04 Maximum current value÷1.50
05 Maximum current value÷1.33
06 Maximum current value÷1.25
07 Maximum current value÷1.20
08 Maximum current value÷1.15
09 Maximum current value÷1.10
10 Maximum current value

So level 3 will be 17.5 A and 840 W at 48V over that your motor will get hot quickly. You could have ordered the 48V 08 battery with the 18A controller inside from BMS it would have saved a lot of work I think.
 

suddenurge

Finding my (electric) wheels
Nov 10, 2015
15
0
48
thanks for the replies.

I am hesitant to open the controller fully because the screws are somewhat stripped. I might give it a try again.

I thought 17.5 amps was pretty much at the upper safe limit for this motor with a 48v battery. What would be a more appropriate max amp level?
 

amigafan2003

Esteemed Pedelecer
Jul 12, 2011
1,389
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Just plugging in a 48v battery to your controller will be perfect for the Q100 - you don't want to go much higher than 800w as they burn out with more watts than that.

I run my Q100 @ 63v, but I've reduced the controller amps down to 14 amps to compensate. I use an EM3EV 6 fet programmable controller - build log here if you're interested - go to the end for build version 3!
 

suddenurge

Finding my (electric) wheels
Nov 10, 2015
15
0
48
Thanks everyone for all the replies.

I borrowed a screwdriver small enough to fully open the controller without stripping the screws. The inside can be described as follows:

8 can shaped things, I assume the capacitors:
1 marked "CL" and "25v 220µF"
4 marked "CL" and "50v 47µF"
1 marked "CL" and "16v 220µF"
1 marked "DL" and "50v 470µF"
1 marked "CT" and "63v 100µF"

7 FETs screwed to a heatsink . They all have the same markings in 3 rows:

"P
HY1607
LA35J G"

Equipped with this information, I would greatly appreciate if someone could give me a definitive answer with regards to compatibility with a 48v battery and also the max amp draw of this controller.

I have concluded that the ideal solution would be to have a controller which can handle both batteries. The 48v would be my main commuter battery, but during the weekends I could use the 36v instead since the plug is the same for both. I realize that I forgot to mention this in my original post
.